Support inference on MacOS with MPS or CPU and add face detection script

[walkoncross]

• inference on MacOS with MPS:

# get reconstruction results of example images
python test.py --name=<model_name> --epoch=20 --img_folder=./datasets/examples --device mps --renderer_type face3d

# no visualization
python test.py --name=<model_name> --epoch=20 --img_folder=./datasets/examples --device mps --renderer_type none --no_viz

• inference on MacOS with CPU:

# get reconstruction results of example images
python test.py --name=<model_name> --epoch=20 --img_folder=./datasets/examples --device cpu --renderer_type face3d

python test.py --name=<model_name> --epoch=20 --img_folder=./datasets/examples --device cpu --renderer_type none --no_viz

• detect faces and landmarks:

python detect_faces_by_insightface.py <folder_to_test_images>